R4 Gordini Turbo

[entwistlecymru]

After Malcolm's Q on my F6 post I thought I'd start a new thread dedicated to my R4 Gordini project. It's been pushed down the list of projects for the moment but I'm still collecting ideas and giving the original plan a huge rethink - I did consider making it mid engined, then I thought better of that!

FOR MALCOLM! I'm using a Renault 5 steering rack which has it's UJ right on the rack (ie lower down then a 4's), just avoiding the manifold. It isn't properly fitted yet though so I'll probably run into problems! I'm also using a modified Gordini column as I've fitted the 5 dash. It's shorter than a 4 column so will give more adjustment up or down, again to avoid the manifold. No pics yet but I'll post some when I've figured it out!

The gear lever handily pops out of the now redundant heater control panel! I've just gotta figure out a way of converting the 'Dini box to dash change We've got a set of 5TS seats trimmed in black suede with red piping, red seatbelts out of a Cinquecento, bright red carpet and I've made up some new doorcards. I'm hoping to use smoked perspex to make up new windows, just to save a bit of weight and save £300 getting the glass tinted.

The front suspension will definitely change - probably junk the torsion bars and fit coilovers (motorbike rear shocks) and fit a 5 roll bar. The coilovers will give adjustable damping and ride height and new springs are only £15 each if I need them.

The rear suspension needs to be lowered, but seeing as I can't find anyone who's managed to do it before I may convert that to coilovers, either using the existing swingarms and a strengthened chassis to stop flex when the torsion bars are taken away OR using the front wishbones, uprights and discs with a radius arm in place of the steering rack. Either way there'll be a lot of fabricating and swearing no doubt.

I'm aiming for 150hp using a GT Turbo carb and intercooler and hybrid turbo. The existing turbo is scrap and a new turbo for small Jap cars are around the £200 mark making them cheaper than getting mine rebuilt. Before doing that though I'll give the engine a proper check over and probably end up rebuilding it to be on the safe side.

Luckily the 4's engine bay is pretty spacious so none of these mods will mean sticking a big bonnet bulge in. Only the Gordini bumpers, alloys, side exit exhaust and 100mm suspension drop will give the game away!

Any thoughts, ideas or tips welcomed! I'm sure I'll have good and bad comments in equal measure

 

[angel]

It sounds very interesting, especially the coilover shocks! Keep us informed on the progress.
P.S. I really dislike the R5 (or any plastic) bumpers on a R4-but this is just personal taste.

 

[entwistlecymru]

I did think about making the car look standard but then I had a thought......What's the point in having a fast car if it doesn't stand out?!

On every car I've owned I've tried to mod them to look factory finshed. The bumpers will need slight reprofiling to fit snugly but hopefully they'll compliment the 4's "lines" (?!) rather than just a big bumper stuck on the front (like it is in the pic!). I know its an acquired taste but you never know Angel, this car may change your opinion

As for the coilovers, apparently there are a few R5 racers using them. I've got Spax shocks for the front anyway but they're a bit grubby and motorbikes shocks are so cheap on eBay it'll be worth the aggro to fit them and have fully adjustable suspension. I've got my eye on a pair with remote reservoirs so they have the potential to be adjusted from inside the car If they work ok on the front, I'll do the same to the back suspension.

Watch this space! :eek:

 

[malcolm]

I like it, and I'm surprised the Gordini bumper fits that well as a starting point. My own Gordini project is going to be completely standard with all the best period R4 bits apart from under the bonnet where it's going to be mostly R5 and my own modifications.

I noticed the R5 rack had a lower down and nore outboard position for the rubber coupling. Though there's a bit of work to do on the chassis to make the mounting points right. I'm going for a R4 rack and a pair of universal joints (from a Ford Fiesta).

For the rear suspension - it is possible to lower them by knocking out the torsion bars and moving them around a few splines. But that would keep the standard ride softness - a bad thing for a lowered car!

 

[bantamallan]

We have tried to separate the rear torsion bars but without success, one has moved about an inch, the other nothing. They have been soaked in releasing oil, heated and severly bashed but no joy We have a spare set we are practising on before we get to the real thing. By the way the cars are mine but my son seems to have taken over, is R4itis hereditary??
Allan

 

[angel]

I had never success trying to release post '77 rear torsion bars as in the manuals. Better remove the complete rear suspension and try to diasassemble the bars on the floor, they will be completely unstressed then.

 

[entwistlecymru]

I've had one rear suspension sitting soaking in releasing oil for months and they still won't budge! It's even got to the stage where I'm planning on cutting swinging arms on one rear suspension to get the torsion bars out and cutting the torsion bars on another to use the swinging arms!

Another possible option would be to do as the rally boys do with roll bars. Cut the bar in the middle and weld a disc onto each bit of the torsion bar. The discs have holes all around the edge so they can be bolted together at different angles to each other. This means I can cut the torsion bars, get each end out to re-bush it etc, lower it and I'll have adjustable rate springing. It's a thought

I'm gonna concentrate on the front suspension first and get that properly sorted, including modding the rack to avoid bump steer (one of the reasons for dodgy handling on seriously lowered cars) and extending the front shock mounts to get a decent sized shock under there. I've got a mate who's a tech freak and designs and builds his own suspension systems for custom cars - he'll be doing all the calculating!!!! Any interesting finds and I'll post them up.